Small Craft Advisory
Also called: SCA
A Small Craft Advisory is a National Weather Service alert for winds or seas that are hazardous to small boats in coastal and Great Lakes waters. The wind and sea thresholds are set separately for each geographic area. There is no precise definition of a small craft: any vessel that the conditions could affect counts.
Key Points
- Thresholds vary by area. On the tidal Potomac River and the Chesapeake Bay, for example, the advisory is issued for sustained winds or frequent gusts of 18 to 33 knots, or waves of 4 feet or higher.
- It can also be issued when sea ice or lake ice is hazardous to small boats.
- Whether it applies to you depends on the boat and the skipper: the vessel's type, size, and seaworthiness, and the operator's experience.
Related Terms
Rip Current
A rip current is a strong, narrow channel of water flowing away from the beach through the surf zone. Rip currents can form on any beach with breaking waves, including the Great Lakes, and can reach 8 feet per second, faster than an Olympic swimmer. They carry swimmers away from shore, not under the water.
King Tide
King tide is a popular, non-scientific name for an exceptionally high tide. King tides happen when the higher tides around a new or full moon coincide with the Moon's closest approach to Earth, called perigee. They can flood low-lying coastal areas on a clear day, and they raise the water level any storm surge is added to.
Watch vs. Warning
A watch means the risk of hazardous weather has risen but its timing, location, or occurrence is still uncertain: be prepared. A warning means hazardous weather is occurring, imminent, or likely and threatens life or property: take action now. An advisory covers events that are occurring or likely but less serious than a warning.
Storm Surge
Storm surge is an abnormal rise in sea level during a hurricane or other intense storm, measured as the height of the water above the normal predicted tide. It is produced mainly by the storm's winds pushing water toward the shore. Storm surge is the leading cause of deaths from hurricanes.
Nor'easter
A storm along the East Coast with winds blowing from the northeast. Nor'easters can bring heavy snow, rain, and coastal flooding, especially from Virginia to New England. The most powerful nor'easters rival hurricanes in intensity.
Small Craft Advisory: Guides and Explainers
These explainers connect this definition to real-world forecasting and decision-making.
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